Re: build a SDB cache for Spatial Database based on postgis

Zhang,
   You'll have better luck posting this question on the postgis-users 
mailing list; this list is for development of the core PostgreSQL 
database.  The subscription page for postgis-users is here:

http://postgis.refractions.net/mailman/listinfo/postgis-users
   Briefly though, at least Oracle, PostgreSQL, IBM DB2, and Informix 
can be configured to store, manipulate, and index geometry types in the 
database.  These are the key features of a spatial database.  Support 
for these capabilities in MySQL seems to be under development.  ArcSDE 
is middleware which is sometimes used to store spatial data in a 
non-spatial database.

-Dave Fuhry

zhang Jackie wrote:
>     I am interesting in PostGis and postgreSQL and want to do something 
> on it. My idea is to build a Spatial Database Cache to accelerate GIS 
> applications .So I want to ask you some question and hope to get your 
> answer.
>     1. As we all know, PostGis is a Spatial extention for PostGreSQL. 
> And there are also some other products such as ArcSDE, Oracle Spatial 
> .Have you ever do some performance comparison between them.If you have 
> ever done such work,Could you give me some information on it. If not, is 
> it because that you team did not care about performance and just 
> concerned with correctness of the program. And if you can give me some 
> materials on performance comparison on such Spatial Database extention 
> including ArcSDE, Oracle Spatial ,MySQL ,etc.
>     2. Since Google Earth is lauched ,Many GIS systems are used by more 
> and more people,so the important features of Software becomes more 
> and more important,such as sacalibity, robust, stability,etc. Can you 
> give me some information and papers on the bottleneck of these 
> applications.Especially, are computing  and I/O requirements very 
> important and become bottlenecks,Of course, If you know some 
> related solutions , you can mail me.
>  I have searche lots of papers and get an overview of it. But I felt I 
> did not figure out the truth. So I want to get some more accurate 
> information on this field.